The present invention relates to electrical systems, and more particularly to high current electrical systems in which a component thereof is subject to replacement.
Electrical systems frequently include replaceable components, as for example fuses. In high current electrical circuits having sufficient voltage, the removal of a component may result in ionization of the air, resulting in an arc discharge as the component looses contact with its mounting member. Arcs of this nature can carry substantial energy, which may result in sufficient heat generation to melt or otherwise damage the component electrical interface and/or its mounting, as well as posing a possible danger of injury to the person performing the extraction. This arc discharge situation, with its concurrent potential for damage and/or injury, may also occur when a component is replaced.
An example of a high current circuit application is the modern automobile. A plethora of electrical devices are now typical in present automobiles, each creating a current draw. These high current electrical circuits have capacitive and inductive aspects which can add transient bursts of current and/or voltage to the circuit. Further, because of the power demand placed upon 12 to 14 volt D.C. automotive electrical systems, consideration is being given to standardize to a higher voltage, for example a 42 volt D.C. electrical system. Higher voltage automotive electrical systems offer reduced current at the same power demand, but the higher voltage may tend to favor arcing when electrical components are proximally separated.
Accordingly, what is needed in the art of high current electrical circuits is a combined system featuring component and personnel protections in the form of fusing, disconnection, and current limitation.
The present invention is a high current disconnect system featuring high current fusing, manual disconnect, and current limitation.
The high current disconnect system includes a fuse, current limiting resistor, a manual disconnection unit, and a holder having a pair of connections for connecting the high current disconnect system to an electrical (ie., automotive) circuit. The fuse, which provides overload protection, is seated in a fuse compartment of the holder and is selectively removable therefrom. The manual disconnection unit is wired in series with the fuse and provides a user selectable circuit interrupt. A first portion of the manual disconnection unit is located in a disconnect compartment of the holder and has the aforesaid series wiring connection, while a second portion thereof is selectively connectable to the first portion, wherein when in the connected state the path therethrough is closed, but when in the disconnected state, the path therethrough is open. The current limiting resistor is wired in parallel with the manual disconnection unit (and also in series with the fuse), and is located in a resistor compartment of the holder. The current limiting resistor provides a current limited path for capacitive and/or inductive elements of the connected electrical circuit during charge or disconnect. In this regard, it will be noted that the parallel arrangement of the manual disconnect and current limiting resistor provides a very low resistance, high current path when the manual disconnect is in its connected state, and a current limited path when the manual disconnect is in its disconnected state. Each of the aforesaid compartments are distinct and a respective cover is provided for each compartment.
The second portion of the manual disconnection unit includes a housing and a bussing assembly. The bussing assembly includes a pair of second terminals which erupt from the housing and a buss bar located within the housing which provides a very low resistance electrical connection between the first terminals. The first portion of the manual disconnection unit includes a pair of first terminals which are configured to connect to the second terminals by a slidable interface therebetween. The housing is structured to adjacently occlude the compartment covers when the first terminals are interfaced with the second terminals (that is, when the manual disconnection unit is in the connected state). Accordingly, to access the fuse or the current limiting resistor, the removable portion of the manual disconnection unit must be separated from the holder (whereupon the manual disconnection unit is in the disconnected state).
Benefits of the present invention include: current limitation and electrical isolation during service of the electrical circuit; multitudinal fuse configurations; small, application specific configurable package; expandability not limited by the number of electrical circuits involved; high reliability involving minimal cabling and components; adaptability to any fusing system; and suitability for integration with existing pre-validated components.
Accordingly, it is an object of the present invention to provide a single package high current manual disconnect system including manual disconnection, fusing and current limitation.
This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.